Many circuits include multiple ground references. These ground references can include separate, isolated return paths for different parts of the circuits. For example, if a circuit includes an analog portion and a digital portion, the analog and digital portions may be coupled to different grounds. Analog and digital grounds are isolated in certain circuits if, for example, the analog circuitry requires a clean ground without noise caused by switching of digital circuitry. The multiple ground references can also include an earth ground or case ground.